Researchers at Maastricht University in the Netherlands examined whether plant-based protein sources can match animal proteins in supporting muscle growth and maintenance for older adults. The findings add to an ongoing conversation about aging, diet, and physical performance, with implications that resonate across Canada and the United States where aging populations are growing and dietary choices are diverse.
The study explored how adults aged 65 to 85 respond when their meals are anchored in different protein sources. In a single-session protocol, participants consumed a meal containing a standard portion of ground beef, providing about 100 grams of meat and a protein content aligned with typical dietary guidelines. On a separate day, the same volunteers were given a meal built from common plant-based ingredients such as quinoa, soy, chickpeas, and kidney beans, prepared in forms familiar to many households. The objective was to compare the body’s muscle-building response to animal versus plant proteins when total calories and total protein were similar between meals.
Muscle protein synthesis was tracked to determine how efficiently each meal prompted the body to assemble new muscle tissue. The beef-based meal achieved a stronger anabolic response, lifting the rate of muscle protein synthesis compared with the plant-based meal that matched it in calories and protein content. In an analysis of amino acids circulating in the bloodstream, the beef meal was associated with a substantially higher increase in the rate of muscle protein synthesis and a pronounced rise in circulating leucine, an essential amino acid known for its pivotal role in initiating muscle fiber formation. The data suggest that, in this specific setting, animal protein provides a more robust stimulus for building muscle mass in older adults when all other nutritional factors are held constant.
These results align with a broader body of research indicating differences in the digestion and amino acid delivery profiles of animal and plant proteins. Researchers emphasize that the total daily protein intake, the distribution of protein across meals, the quality of the protein source, and the overall pattern of training and physical activity all influence the muscle-building outcome. For individuals in Canada and the United States who are weighing dietary choices, the takeaway centers on planning meals that meet protein needs while supporting muscle health, especially for those facing aging-associated changes in metabolism and activity levels.
Experts point out that vegetarian and vegan eating patterns can still support muscle maintenance through thoughtful protein planning. This includes choosing plant proteins with complementary amino acid profiles, using fortified products, and incorporating regular resistance exercise to maximize muscle protein responses. The current findings do not deny the value of plant-based diets for environmental, ethical, or health reasons but highlight that, in a direct comparison under controlled conditions, animal protein may offer a stronger immediate stimulus for muscle synthesis in older adults. Ongoing research continues to explore optimization strategies—such as timing protein intake around workouts and combining diverse plant sources—to narrow the gap in anabolic potential where it exists. In practice, many adults can achieve robust muscle health by balancing protein quality, total intake, and physical activity, regardless of dietary pattern.